<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button onclick="alert('hello')">button</button>
    <div onclick="alert('hello')">div</div>
    <script>
        const button = document.querySelector('button');
        console.dir(button);
        function handleClick(){
            console.log(this);
        }
        button.onclick = handleClick
        const div = document.querySelector('div');
        div.onclick = handleClick
    </script>
</body>
</html>